SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73dfda825a8d9c176adf26cbb0693608e685674af69b7851cccd6fcf868d396a' 
  AND token = 'nzNnGOzl7bRZBNi6nMxLN1URbK/moFOLwZxFhWspSHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}